Acrylic Syrup Bulk Photopolymerization UV Control
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Solution Overview
Problem
Existing acrylic syrup preparation methods face challenges such as environmental hazards from solvent evaporation, complex additive processes, low productivity, and surface appearance issues due to molecular weight adjusting agents in bulk polymerization, particularly in solution and emulsion polymerization, and instability in bulk thermal and photopolymerization.
Innovation Solution
A bulk photopolymerization method involving UV irradiation of a composition containing a photoinitiator and acrylic monomers, with controlled temperature increase and purging using an oxygen-containing inert gas to prevent explosive reactions and molecular weight adjusting agent migration, ensuring desired conversion rates and storage stability without these agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If bulk photopolymerization is used to achieve high productivity, then the reaction rate increases, but the reaction may explosively occur and it is difficult to uniformly prepare an acrylic syrup having a desired level of conversion rate
Solution Approach 1:
The patent applies periodic action by controlling UV irradiation in a cyclic manner: irradiating for a first period of time to initiate polymerization, then stopping irradiation for a second period of time to allow temperature equalization. This periodic on-off irradiation pattern prevents explosive reactions while maintaining high conversion rates by repeatedly cycling through polymerization and stabilization phases.
Solution Approach 2:
The patent applies preliminary action by pre-cooling the reaction mixture to a specific temperature range (5-25°C) before initiating UV irradiation, and by pre-establishing the polymerization system with all necessary components (monomers, photoinitiator) properly mixed. This preliminary preparation ensures that when irradiation begins, the reaction proceeds controllably without explosive temperature increases.
2Reliability
If molecular weight adjusting agents are used to control reaction explosiveness, then reaction safety improves, but the agents remain in the acrylic syrup and migrate to the product surface, deteriorating surface appearance and performance
Solution Approach 1:
The patent applies the taking out principle by completely eliminating molecular weight adjusting agents from the polymerization system. Instead of using these agents to control reaction safety, the patent achieves safe controlled polymerization through periodic UV irradiation and temperature management, thereby extracting the harmful substance from the system while maintaining reaction control.
Solution Approach 2:
The patent converts the potentially harmful rapid exothermic reaction into a beneficial controlled process by using periodic UV irradiation. The heat generated during polymerization is no longer a problem to be suppressed by chemical agents but is managed through controlled irradiation cycles, allowing the reaction energy to be harnessed for complete monomer conversion without explosive temperature increases.
3Ease of manufacture
If solution polymerization is used to prepare acrylic syrup, then the polymerization process can proceed, but an organic solvent remains in the acrylic syrup which may generate odor, fire, explosion, and atmospheric contamination
Solution Approach 1:
The patent applies the taking out principle by completely removing organic solvents from the polymerization system. The invention uses bulk polymerization of pure acrylic monomers without any solvent, thereby extracting the source of environmental hazards (odor, fire, explosion risks, atmospheric contamination) while maintaining an effective polymerization process through UV irradiation.
Solution Approach 2:
The patent creates an inert environment by conducting polymerization of pure monomers without oxygen exposure (using nitrogen or argon atmosphere) and without organic solvents. This inert environment eliminates fire and explosion hazards associated with organic solvents while allowing controlled photopolymerization to proceed to high conversion rates.
4Object-generated harmful factors
If emulsion polymerization is used to avoid organic solvents, then environmental safety improves, but a large amount of water is used and a large amount of waste water is generated
Solution Approach 1:
The patent applies the taking out principle by removing water (the continuous phase in emulsion polymerization) from the system. Instead of using water-based emulsion polymerization, the invention performs bulk polymerization of pure acrylic monomers, thereby extracting the source of waste water generation while maintaining environmental safety through the use of UV-initiated polymerization without harmful solvents.
Solution Approach 2:
The patent uses inexpensive, easily removable nitrogen or argon atmosphere as a temporary protective environment during polymerization, which is then simply vented. This replaces the need for large amounts of water used in emulsion polymerization, eliminating waste water generation while maintaining reaction control and environmental safety.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves eco-friendliness, high productivity, excellent storage stability, and uniform performance by preventing explosive reactions and surface appearance issues, maintaining consistent physical properties over temperature and light exposure without the need for molecular weight adjusting agents.
Implementation Method 1
performing bulk photopolymerization by initiating a UV irradiation of a composition containing a photoinitiator and one or more types of acrylic monomers
Implementation Method 2
purging the composition with an oxygen-containing inert gas after the UV irradiation is stopped
Data Source
AI summary
Provided is an acrylic syrup preparation method including the steps of: performing bulk photopolymerization by initiating a UV irradiation of a composition containing a photoinitiator and one or more types of acrylic monomers; stopping the UV irradiation at the time point when the temperature is increased by about 5° C. to about 40° C. from the time point when the temperature at which the UV irradiation of the composition is initiated; and purging the composition with an oxygen-containing inert gas after the UV irradiation is stopped.